/**
 * TabataFit Home Screen
 * React Native UI — wired to shared data
 */

import { View, StyleSheet, ScrollView, Pressable, Dimensions, Text as RNText, Image as RNImage } from 'react-native'
import { useRouter } from 'expo-router'
import { useSafeAreaInsets } from 'react-native-safe-area-context'
import { LinearGradient } from 'expo-linear-gradient'
import { BlurView } from 'expo-blur'
import Ionicons from '@expo/vector-icons/Ionicons'

import { useMemo } from 'react'
import { useHaptics } from '@/src/shared/hooks'
import { useUserStore, useActivityStore } from '@/src/shared/stores'
import {
  getFeaturedWorkouts,
  getPopularWorkouts,
  getTrainerById,
  COLLECTIONS,
  WORKOUTS,
} from '@/src/shared/data'
import { StyledText } from '@/src/shared/components/StyledText'

import {
  BRAND,
  DARK,
  TEXT,
  GLASS,
  SHADOW,
  GRADIENTS,
} from '@/src/shared/constants/colors'
import { SPACING, LAYOUT } from '@/src/shared/constants/spacing'
import { RADIUS } from '@/src/shared/constants/borderRadius'

const { width: SCREEN_WIDTH } = Dimensions.get('window')
const CARD_WIDTH = SCREEN_WIDTH - LAYOUT.SCREEN_PADDING * 2

const FONTS = {
  LARGE_TITLE: 34,
  TITLE: 28,
  TITLE_2: 22,
  HEADLINE: 17,
  BODY: 17,
  SUBHEADLINE: 15,
  CAPTION_1: 12,
  CAPTION_2: 11,
}

// ═══════════════════════════════════════════════════════════════════════════
// HELPERS
// ═══════════════════════════════════════════════════════════════════════════

function getGreeting() {
  const hour = new Date().getHours()
  if (hour < 12) return 'Good morning'
  if (hour < 18) return 'Good afternoon'
  return 'Good evening'
}

function PrimaryButton({ children, onPress }: { children: string; onPress?: () => void }) {
  return (
    <Pressable style={styles.primaryButton} onPress={onPress}>
      <Ionicons name="play" size={16} color={TEXT.PRIMARY} style={styles.buttonIcon} />
      <RNText style={styles.primaryButtonText}>{children}</RNText>
    </Pressable>
  )
}

function PlainButton({ children, onPress }: { children: string; onPress?: () => void }) {
  return (
    <Pressable onPress={onPress}>
      <RNText style={styles.plainButtonText}>{children}</RNText>
    </Pressable>
  )
}

// ═══════════════════════════════════════════════════════════════════════════
// MAIN SCREEN
// ═══════════════════════════════════════════════════════════════════════════

export default function HomeScreen() {
  const insets = useSafeAreaInsets()
  const router = useRouter()
  const haptics = useHaptics()
  const userName = useUserStore((s) => s.profile.name)
  const history = useActivityStore((s) => s.history)
  const recentWorkouts = useMemo(() => history.slice(0, 3), [history])

  const featured = getFeaturedWorkouts()[0] ?? WORKOUTS[0]
  const featuredTrainer = getTrainerById(featured.trainerId)
  const popular = getPopularWorkouts(4)

  const handleWorkoutPress = (id: string) => {
    haptics.buttonTap()
    router.push(`/workout/${id}`)
  }

  return (
    <View style={[styles.container, { paddingTop: insets.top }]}>
      <ScrollView
        style={styles.scrollView}
        contentContainerStyle={[styles.scrollContent, { paddingBottom: insets.bottom + 100 }]}
        showsVerticalScrollIndicator={false}
      >
        {/* Header */}
        <View style={styles.header}>
          <StyledText size={FONTS.LARGE_TITLE} weight="semibold" color={TEXT.PRIMARY}>
            {getGreeting() + ', ' + userName}
          </StyledText>
          <Pressable style={styles.profileButton}>
            <Ionicons name="person-circle-outline" size={32} color={TEXT.PRIMARY} />
          </Pressable>
        </View>

        {/* Featured */}
        <Pressable
          style={styles.featuredCard}
          onPress={() => handleWorkoutPress(featured.id)}
        >
          {featured.thumbnailUrl ? (
            <RNImage
              source={{ uri: featured.thumbnailUrl }}
              style={StyleSheet.absoluteFill}
              resizeMode="cover"
            />
          ) : (
            <LinearGradient
              colors={[BRAND.PRIMARY, BRAND.PRIMARY_DARK]}
              style={StyleSheet.absoluteFill}
            />
          )}
          <LinearGradient
            colors={GRADIENTS.VIDEO_OVERLAY}
            style={StyleSheet.absoluteFill}
          />

          <View style={styles.featuredBadge}>
            <RNText style={styles.featuredBadgeText}>🔥 FEATURED</RNText>
          </View>

          <View style={styles.featuredContent}>
            <StyledText size={FONTS.TITLE} weight="bold" color={TEXT.PRIMARY}>
              {featured.title}
            </StyledText>
            <StyledText size={FONTS.SUBHEADLINE} color={TEXT.SECONDARY}>
              {featured.duration + ' min • ' + featured.level + ' • ' + (featuredTrainer?.name ?? '')}
            </StyledText>

            <View style={styles.featuredButtons}>
              <PrimaryButton onPress={() => handleWorkoutPress(featured.id)}>START</PrimaryButton>
              <Pressable style={styles.saveButton}>
                <Ionicons name="heart-outline" size={24} color={TEXT.PRIMARY} />
              </Pressable>
            </View>
          </View>
        </Pressable>

        {/* Continue Watching — from activity store */}
        {recentWorkouts.length > 0 && (
          <View style={styles.section}>
            <View style={styles.sectionHeader}>
              <StyledText size={FONTS.TITLE_2} weight="semibold" color={TEXT.PRIMARY}>Recent</StyledText>
              <PlainButton>See All</PlainButton>
            </View>
            <ScrollView
              horizontal
              showsHorizontalScrollIndicator={false}
              contentContainerStyle={styles.horizontalScroll}
            >
              {recentWorkouts.map((result) => {
                const workout = WORKOUTS.find(w => w.id === result.workoutId)
                if (!workout) return null
                const trainer = getTrainerById(workout.trainerId)
                return (
                  <Pressable
                    key={result.id}
                    style={styles.continueCard}
                    onPress={() => handleWorkoutPress(result.workoutId)}
                  >
                    <View style={styles.continueThumb}>
                      <LinearGradient
                        colors={[trainer?.color ?? BRAND.PRIMARY, BRAND.PRIMARY_LIGHT]}
                        style={StyleSheet.absoluteFill}
                      />
                      <StyledText size={FONTS.LARGE_TITLE} weight="bold" color={TEXT.PRIMARY}>
                        {trainer?.name[0] ?? 'T'}
                      </StyledText>
                    </View>
                    <StyledText size={FONTS.SUBHEADLINE} weight="semibold" color={TEXT.PRIMARY}>{workout.title}</StyledText>
                    <StyledText size={FONTS.CAPTION_2} color={TEXT.TERTIARY}>
                      {result.calories + ' cal • ' + result.durationMinutes + ' min'}
                    </StyledText>
                  </Pressable>
                )
              })}
            </ScrollView>
          </View>
        )}

        {/* Popular This Week */}
        <View style={styles.section}>
          <StyledText size={FONTS.TITLE_2} weight="semibold" color={TEXT.PRIMARY}>Popular This Week</StyledText>
          <ScrollView
            horizontal
            showsHorizontalScrollIndicator={false}
            contentContainerStyle={styles.horizontalScroll}
          >
            {popular.map((item) => (
              <Pressable
                key={item.id}
                style={styles.popularCard}
                onPress={() => handleWorkoutPress(item.id)}
              >
                <View style={styles.popularThumb}>
                  <Ionicons name="flame" size={24} color={BRAND.PRIMARY} />
                </View>
                <StyledText size={FONTS.SUBHEADLINE} weight="medium" color={TEXT.PRIMARY}>{item.title}</StyledText>
                <StyledText size={FONTS.CAPTION_2} color={TEXT.TERTIARY}>{item.duration + ' min'}</StyledText>
              </Pressable>
            ))}
          </ScrollView>
        </View>

        {/* Collections */}
        <View style={styles.section}>
          <StyledText size={FONTS.TITLE_2} weight="semibold" color={TEXT.PRIMARY}>Collections</StyledText>
          {COLLECTIONS.map((item) => (
            <Pressable key={item.id} style={styles.collectionCard} onPress={() => { haptics.buttonTap(); router.push(`/collection/${item.id}`) }}>
              <BlurView intensity={GLASS.BLUR_MEDIUM} tint="dark" style={StyleSheet.absoluteFill} />
              <View style={styles.collectionContent}>
                <RNText style={styles.collectionIcon}>{item.icon}</RNText>
                <View style={styles.collectionText}>
                  <StyledText size={FONTS.HEADLINE} weight="semibold" color={TEXT.PRIMARY}>{item.title}</StyledText>
                  <StyledText size={FONTS.CAPTION_1} color={TEXT.TERTIARY}>
                    {item.workoutIds.length + ' workouts • ' + item.description}
                  </StyledText>
                </View>
                <Ionicons name="chevron-forward" size={20} color={TEXT.TERTIARY} />
              </View>
            </Pressable>
          ))}
        </View>
      </ScrollView>
    </View>
  )
}

// ═══════════════════════════════════════════════════════════════════════════
// STYLES
// ═══════════════════════════════════════════════════════════════════════════

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: DARK.BASE,
  },
  scrollView: {
    flex: 1,
  },
  scrollContent: {
    paddingHorizontal: LAYOUT.SCREEN_PADDING,
  },

  // Header
  header: {
    flexDirection: 'row',
    justifyContent: 'space-between',
    alignItems: 'center',
    marginBottom: SPACING[6],
  },
  profileButton: {
    width: 40,
    height: 40,
    alignItems: 'center',
    justifyContent: 'center',
  },

  // Buttons
  primaryButton: {
    flexDirection: 'row',
    alignItems: 'center',
    backgroundColor: BRAND.PRIMARY,
    paddingHorizontal: SPACING[4],
    paddingVertical: SPACING[3],
    borderRadius: RADIUS.SM,
  },
  buttonIcon: {
    marginRight: SPACING[2],
  },
  primaryButtonText: {
    fontSize: 14,
    fontWeight: '600',
    color: TEXT.PRIMARY,
  },
  plainButtonText: {
    fontSize: FONTS.BODY,
    color: BRAND.PRIMARY,
  },

  // Featured
  featuredCard: {
    width: CARD_WIDTH,
    height: 220,
    borderRadius: RADIUS.GLASS_CARD,
    overflow: 'hidden',
    marginBottom: SPACING[8],
    ...SHADOW.lg,
  },
  featuredBadge: {
    position: 'absolute',
    top: SPACING[4],
    left: SPACING[4],
    backgroundColor: 'rgba(255, 255, 255, 0.15)',
    paddingHorizontal: SPACING[3],
    paddingVertical: SPACING[1],
    borderRadius: RADIUS.SM,
    borderWidth: 1,
    borderColor: 'rgba(255, 255, 255, 0.2)',
  },
  featuredBadgeText: {
    fontSize: 11,
    fontWeight: 'bold',
    color: TEXT.PRIMARY,
  },
  featuredContent: {
    position: 'absolute',
    bottom: 0,
    left: 0,
    right: 0,
    padding: SPACING[5],
  },
  featuredButtons: {
    flexDirection: 'row',
    alignItems: 'center',
    gap: SPACING[3],
    marginTop: SPACING[4],
  },
  saveButton: {
    width: 44,
    height: 44,
    alignItems: 'center',
    justifyContent: 'center',
    backgroundColor: 'rgba(255, 255, 255, 0.1)',
    borderRadius: 22,
    borderWidth: 1,
    borderColor: 'rgba(255, 255, 255, 0.15)',
  },

  // Sections
  section: {
    marginBottom: SPACING[8],
  },
  sectionHeader: {
    flexDirection: 'row',
    justifyContent: 'space-between',
    alignItems: 'center',
    marginBottom: SPACING[4],
  },
  horizontalScroll: {
    gap: SPACING[3],
  },

  // Continue Card
  continueCard: {
    width: 140,
  },
  continueThumb: {
    width: 140,
    height: 200,
    borderRadius: RADIUS.LG,
    overflow: 'hidden',
    alignItems: 'center',
    justifyContent: 'center',
    marginBottom: SPACING[2],
  },

  // Popular Card
  popularCard: {
    width: 120,
  },
  popularThumb: {
    width: 120,
    height: 120,
    borderRadius: RADIUS.LG,
    alignItems: 'center',
    justifyContent: 'center',
    marginBottom: SPACING[2],
    borderWidth: 1,
    borderColor: 'rgba(255, 255, 255, 0.1)',
    backgroundColor: 'rgba(255, 255, 255, 0.05)',
  },

  // Collection Card
  collectionCard: {
    height: 80,
    borderRadius: RADIUS.LG,
    overflow: 'hidden',
    marginBottom: SPACING[3],
    borderWidth: 1,
    borderColor: 'rgba(255, 255, 255, 0.1)',
  },
  collectionContent: {
    flex: 1,
    flexDirection: 'row',
    alignItems: 'center',
    paddingHorizontal: SPACING[5],
  },
  collectionIcon: {
    fontSize: 28,
    marginRight: SPACING[4],
  },
  collectionText: {
    flex: 1,
  },
})